Amgen's Stock Slides to 220th in U.S. Trading Volume Amid 27.27% Drop in Daily Dollar Volume

On October 6, 2025, Amgen (AMGN) closed at a 1.27% decline with a trading volume of $0.55 billion, representing a 27.27% drop from the prior day’s activity. The stock ranked 220th in trading volume among U.S. equities, reflecting muted market engagement despite its market capitalization.

Recent developments suggest mixed sentiment toward the biotech giant. The European Commission approved Amgen’s biosimilar version of Humira, expanding its competitive edge in the biosimilars market. However, delays in disclosing Phase III trial data for its experimental cancer therapy RO5533493 have raised concerns about potential setbacks in its late-stage pipeline. Analysts note that the lack of near-term catalysts—beyond the biosimilar launch—may limit upward momentum in the near term.

Internally, the company faces leadership uncertainty after its head of global manufacturing announced plans to retire earlier than scheduled. While the transition is expected to be orderly, investors remain cautious about the implications for operational continuity. Meanwhile, regulatory scrutiny over pricing practices in key markets continues to weigh on long-term growth expectations, particularly in Europe.

To run a rigorous back-test I’ll need to nail down a few practical details first: 1. Universe – “Top 500 stocks by daily trading volume” – should I rank across all U.S. listed common stocks, S&P 500 constituents, or another universe? 2. Entry & exit timing – Volume for ranking is only known after the market close. A common implementation is: Rank yesterday’s volume (T-1), buy the selected names at today’s (T) open, and sell at today’s close (holding period ≈ 1 trading day). Does that suit you, or would you prefer buy at the close and sell next-day close? 3. Weighting scheme – Equal-weighting each of the 500 names each day (typical), or value-weighting by traded dollar volume? 4. Transaction costs / slippage – Should we assume zero cost, or apply a cost (e.g., 5 bps in & out) to make the test more realistic? Once these items are confirmed I can generate the signal file and run the back-test from 2022-01-03 through today (2025-10-06).